1. Field of the Invention
The invention relates to a computer-implemented method for creating a model of a technical system on a computer which has at least one display. The model can include at least two model components of the same class, and each model component can have at least one input and/or at least one output, whereby links are established between the inputs and outputs of the model components.
2. Description of the Background Art
Computer-implemented methods for creating a model are known and are a permanent part of mathematical/physical modeling of a technical system, one of the best known methods being the computer-assisted creation of block diagrams. Block diagrams of this type have different blocks as model components, each block having a certain functionality which may include, for example the functionality of a data source—for example in the form of a mathematically simulated signal generator—which may have the functionality of a data sink, for example, a recording of data obtained via the input on a storage medium of the computer, and which may have, for example, a transmission function. Model components of the latter type output a signal via the block output which is the result of the signal which is modified according to the transmission behavior of the block and which the corresponding block has received via one of its inputs. In the case of block diagrams, links in the form of signal lines that indicate how signals flow within the block diagram are provided between the inputs and outputs of the model components designed as blocks. A computer-implemented method of this type for creating a model is offered, for example, by the MATLAB modeling environment, together with the Simulink graphical user interface from The Math Works, Inc.
Other computer-implemented methods for creating a model may make do without the classic linking of model components via signal lines. A relationship between the different model components may then be identified, for example, simply by using corresponding names of state variables. The specific implementation of links between model components is of no consequence in this case. The links between the model components are generally used entirely for the purpose of demonstrating the effective relationship between the different model components.
Generally, when a computer-implemented method for creating a model on a computer is discussed, it is typically meant that the method may be automated or carried out with the aid of a computer. The computer may be a commercially available PC (personal computer) having an arithmetic unit, main memory and mass storage of an input unit and a display, a workstation or even a distributed work environment; the specific equipment of the computer is of no consequence.
Models of technical systems or of parts of technical systems are frequently created in order to interact with real technical systems or with parts of real technical systems, for example in developing control units or in developing controllers/regulators to be implemented on control units. The control unit is often concretely provided in the form of hardware to be tested which has suitable I/O interfaces. To reliably and easily test the control unit, the environment of the control unit (physical process) is modeled with the aid of a mathematical model in a simulator which is able to calculate the physical process in real time. The variables to be detected by the control unit using measurement and to be output by the control unit as the response are output or detected by measurement via appropriately programmable I/O interfaces of the simulator. The test method described above is also referred to as hardware-in-the-loop simulation. Other applications for creating models of technical systems are combined, for example, under the term “rapid control prototyping.” To return to the aforementioned structure, the control unit and the regulator implemented on the control unit are simulated, in practical terms, and tested together with the real technical process. In both test scenarios for which the model of a technical system or part of a technical system is to be created, the different areas of the test system, i.e., the control unit hardware, I/O interfaces of the simulator and the mathematical model of the technical process on the simulator, are handled separately from each other.
When the model includes at least two model components of the same class, it is typically understood that the model components come from only one of the areas illustrated above, i.e., they are either model components of the mathematical model or model components of an I/O interface or model components of actually existing hardware. The present case does not concern models which come from multiple areas of a previously demonstrated test and development system but only model components which come from one of these areas. Model components that come from one of the areas illustrated above—actually existing hardware, actually existing I/O interfaces or parts of the mathematical model—are model components of the same class.
Models of technical systems may be very comprehensive and—depending on the complexity of the underlying technical system—may contain several thousand model components of the same class. Models of this type may be very unclear, since they extend over a large area on the computer display, and therefore only a small portion of the model as a whole may often be viewed by the computer user. This problem is even worse when the model of the technical system extends over multiple hierarchical levels. In the case of a model created as a block diagram, this means, for example, that model components provided as blocks are nested within each other, i.e., a block has a plurality of blocks on an underlying modeling level, and these blocks, in turn, may include multiple additional blocks on even lower modeling levels. The viewer of a model of this type may gain an overview of the functional structure thereof only on one hierarchical level of a single model component, which makes it more difficult to gain an overall understanding of the modeled relationship or relationship still to be modeled.